Fix bug with CHA dependencies by recording a set of classes for registering code.

tests/language/cha_deopt1_test.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// VMOptions=--optimization-counter-threshold=100
+
+// Test lazy deoptimization at field guards with deferred loading.
+
+import "package:expect/expect.dart";
+import "cha_deopt1_lib.dart";
+import "cha_deopt1_deferred_lib.dart" deferred as d;
+
+var loaded = false;
+
+main() {
+  for (var i = 0; i < 2000; i++) bla();
+  Expect.equals(42, bla());
+  d.loadLibrary().then((_) {
+    loaded = true;
+    Expect.equals("good horse", bla());
+  });
+}
+
+make_t() {
+  try {
+    if (loaded) {
+      return d.make_u();
+    } else {
+      return new T();
+    }
+  } catch (e) { }
+}
+
+bla() {
+  var x = new X();
+  x.test(make_t());
+  return x.fld.m();
+}
+
+
+class X {
+  T fld = new T();
+
+  test(T t) {
+    if (t != null) {
+      T tmp = t;
+      fld = tmp;
+    }
+  }
+}
+